Re: [PATCH v2 2/3] ia64: thin archives fix linking

[Nicholas Piggin <npiggin@gmail.com>]

On Fri, 23 Jun 2017 18:56:32 +0900
Masahiro Yamada <yamada.masahiro@socionext.com> wrote:

> Hi Nicholas,
> 
> 
> 2017-06-22 21:39 GMT+09:00 Nicholas Piggin <npiggin@gmail.com>:


> Without this patch,
> 
> $ ia64-linux-nm -n arch/ia64/kernel/gate-syms.o
> a000000000000600 D __start_gate_mckinley_e9_patchlist
> a000000000000604 D __end_gate_mckinley_e9_patchlist
> a000000000000604 D __end_gate_vtop_patchlist
> a000000000000604 D __start_gate_fsyscall_patchlist
> a000000000000604 D __start_gate_vtop_patchlist
> a000000000000608 D __end_gate_fsyscall_patchlist
> a000000000000608 D __start_gate_brl_fsys_bubble_down_patchlist
> a00000000000060c D __end_gate_brl_fsys_bubble_down_patchlist
> a000000000040720 T __kernel_syscall_via_break
> a000000000040740 T __kernel_sigtramp
> a000000000040770 t back_from_setup_rbs
> a000000000040830 t back_from_restore_rbs
> a0000000000408a0 t setup_rbs
> a000000000040900 t restore_rbs
> a000000000040a00 T __kernel_syscall_via_epc
> 
> $ ia64-linux-nm -n arch/ia64/kernel/built-in.o | grep  __kernel_sigtramp
> a000000000040740 A __kernel_sigtramp
> 
> 
> With this patch,
> 
> $ ia64-linux-nm -n arch/ia64/kernel/gate-syms.o
> 0000000000000000 A __kernel_syscall_via_break

> 0000000000000020 A __kernel_sigtramp
> 00000000000002e0 A __kernel_syscall_via_epc
> a000000000000600 D __end_gate_brl_fsys_bubble_down_patchlist
> a000000000000600 D __end_gate_fsyscall_patchlist
> a000000000000600 D __end_gate_mckinley_e9_patchlist
> a000000000000600 D __end_gate_vtop_patchlist
> a000000000000600 D __start_gate_brl_fsys_bubble_down_patchlist
> a000000000000600 D __start_gate_fsyscall_patchlist
> a000000000000600 D __start_gate_mckinley_e9_patchlist
> a000000000000600 D __start_gate_vtop_patchlist
> 
> $ ia64-linux-nm -n arch/ia64/kernel/built-in.o | grep __kernel_sigtramp
> 0000000000000020 A __kernel_sigtramp
> 
> 
> Could you check it?

Sorry about this, thank you for catching it.

This needs a dummy .o file as well. It seems we cannot do both -T and -R
operations in one step. This patch follows more like sh and tile fixes.

Thanks,
Nick

---
 arch/ia64/kernel/Makefile.gate | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/arch/ia64/kernel/Makefile.gate b/arch/ia64/kernel/Makefile.gate
index a32903ada016..e8ca862e7b21 100644
--- a/arch/ia64/kernel/Makefile.gate
+++ b/arch/ia64/kernel/Makefile.gate
@@ -1,8 +1,10 @@
 # The gate DSO image is built using a special linker script.
 
-targets += gate.so gate-syms.o
+targets += gate.so gate-syms.o gate-dummy.o
 
-extra-y += gate.so gate-syms.o gate.lds gate.o
+obj-y += gate-syms.o
+
+extra-y += gate.so gate.lds gate.o
 
 CPPFLAGS_gate.lds := -P -C -U$(ARCH)
 
@@ -14,13 +16,17 @@ GATECFLAGS_gate.so = -shared -s -Wl,-soname=linux-gate.so.1 \
 $(obj)/gate.so: $(obj)/gate.lds $(obj)/gate.o FORCE
 	$(call if_changed,gate)
 
-$(obj)/built-in.o: $(obj)/gate-syms.o
-$(obj)/built-in.o: ld_flags += -R $(obj)/gate-syms.o
+# create an object file to resolve gate symbols
+quiet_cmd_gate_syms = GATESYM $@
+      cmd_gate_syms = $(LD) -r -R $(obj)/gate-dummy.o -o $@
 
-GATECFLAGS_gate-syms.o = -r
-$(obj)/gate-syms.o: $(obj)/gate.lds $(obj)/gate.o FORCE
+GATECFLAGS_gate-dummy.o = -r
+$(obj)/gate-dummy.o: $(obj)/gate.lds $(obj)/gate.o FORCE
 	$(call if_changed,gate)
 
+$(obj)/gate-syms.o: $(obj)/gate-dummy.o FORCE
+	$(call if_changed,gate_syms)
+
 # gate-data.o contains the gate DSO image as data in section .data..gate.
 # We must build gate.so before we can assemble it.
 # Note: kbuild does not track this dependency due to usage of .incbin
-- 
2.11.0